Planet Jupiter: Facts About Its Size, Moons and Red Spot Planet Jupiter: Facts About Its Size, Moons and Red Spot By Charles Q. Choi, Space.com Contributor | November 14, 2014 12:59am ET MORE This photo of Jupiter was taken on Sept. 20, 2010 when Jupiter made its closest approach to Earth since 1963. (Uranus [insert] was visible through telescopes near Jupiter.) Credit: Jimmy Eubanks Jupiter is the largest planet in the solar system. Fittingly, it was named after the king of the gods in Roman mythology. In a similar manner, the ancient Greeks named the planet after Zeus, the king of the Greek pantheon. Jupiter helped revolutionize the way we saw the universe and ourselves in 1610, when Galileo discovered Jupiter's four large moons — Io, Europa, Ganymede and Callisto, now known as the Galilean moons. This was the first time celestial bodies were seen circling an object other than Earth, major support of the Copernican view that Earth was not the center of the universe.

Physical characteristics Jupiter is the most massive planet in our solar system , more than twice as massive as all the other planets combined, and had it been about 80 times more massive, it would have actually become a star instead of a planet. Its atmosphere resembles that of the sun, made up mostly of hydrogen and helium, and with four large moons and many smaller moons in orbit around it, Jupiter by itself forms a kind of miniature solar system. All told, the immense volume of Jupiter could hold more than 1,300 Earths. The colorful bands of Jupiter are arranged in dark belts and light zones created by strong east-west winds in the planet's upper atmosphere traveling more than 400 mph (640 kph). The white clouds in the zones are made of crystals of frozen ammonia, while darker clouds of other chemicals are found in the belts. At the deepest visible levels are blue clouds. Far from being static, the stripes of clouds change over time . Inside the atmosphere, diamond rain may fill the skies. The most extraordinary feature on Jupiter is undoubtedly the Great Red Spot , a giant hurricane-like storm seen for more than 300 years.

At its widest, the Great Red Spot is three times the diameter of the Earth, and its edge spins counterclockwise around its center at a speed of about 225 mph (360 kph). The color of the storm, which usually varies from brick red to slightly brown, may come from small amounts of sulfur and phosphorus in the ammonia crystals in Jupiter's clouds. The spot grows and shrinks over time, and every now and again, seems to fade entirely. Jupiter's gargantuan magnetic field is the strongest of all the planets in the solar system at nearly 20,000 times the strength of Earth's. It traps electrically charged particles in an intense belt of electrons and other electrically charged particles that regularly blasts the planet's moons and rings with a level of radiation more than 1,000 times the lethal level for a human, damaging even heavily shielded spacecraft such as NASA's Galileo probe.

The magnetosphere of Jupiter, which is composed of these fields and particles, swells out some 600,000 to 2 million miles (1 million to 3 million km) toward the sun and tapers to a tail extending more than 600 million miles (1 billion km) behind Jupiter. Jupiter spins faster than any other planet, taking a little under 10 hours to complete a turn on its axis, compared with 24 hours for Earth. This rapid spin makes Jupiter bulge at the equator and flatten at the poles, making the planet about 7 percent wider at the equator than at the poles. Jupiter broadcasts radio waves strong enough to detect on Earth. These come in two forms — strong bursts that occur when Io, the closest of Jupiter's large moons, passes through certain regions of Jupiter's magnetic field, and continuous radiation from Jupiter's surface and high-energy particles in its radiation belts. These radio waves could help scientists to probe the oceans on its moons.

Composition & structure Atmospheric composition (by volume): 89.8 percent molecular hydrogen, 10.2 percent helium, minor amounts of methane, ammonia, hydrogen deuteride, ethane, water, ammonia ice aerosols, water ice aerosols, ammonia hydrosulfide aerosols Magnetic field: Nearly 20,000 times stronger than Earth's Chemical composition: Jupiter has a dense core of uncertain composition , surrounded by a helium-rich layer of fluid metallic hydrogen, wrapped up in an atmosphere primarily made of molecular hydrogen. Internal structure: A core less than 10 times Earth's mass surrounded by a layer of fluid metallic hydrogen extending out to 80 to 90 percent of the diameter of the planet, enclosed in an atmosphere mostly made of gaseous and liquid hydrogen. Orbit & rotation Average distance from the sun : 483,682,810 miles (778,412,020 km). By comparison: 5.203 times that of Earth Perihelion (closest approach to the sun): 460,276,100 miles (740,742,600 km).

By comparison: 5.036 times that of Earth Aphelion (farthest distance from the sun): 507,089,500 miles (816,081,400 km). By comparison: 5.366 times that of Earth (Source: NASA .) Jupiter's moons Jupiter has at least 63 moons , which are often named after the Roman god's many lovers. The four largest moons of Jupiter, now called Io, Europa, Ganymede, and Callisto, were discovered by Galileo Galilei himself, and are appropriately known today as the Galilean satellites. Ganymede is the largest moon in our solar system, larger even than Mercury and Pluto. It is also the only moon known to have its own magnetic field. The moon has at least one thick ocean between layers of ice, although it may contain several layers of both materials. Io is the most volcanically active body in our solar system. The sulfur its volcanoes spew out gives Io a blotted yellow-orange appearance that is often compared to a pepperoni pizza.

As Io orbits Jupiter, the planet's immense gravity causes 'tides' in Io's solid surface that rise 300 feet (100 meters) high, generating enough heat for volcanic activity. The frozen crust of Europa is made up mostly of water ice, and it may hide a liquid ocean holding twice as much water as Earth does. Icy oceans may also exist beneath the crusts of Callisto and Ganymede. Some of this liquid spouts from the surface in newly spotted sporadic plumes at the southern pole. Its potential to host life caused NASA to request funding for a mission to explore Europa . Callisto has the lowest reflectivity, or albedo, of the four Galilean moons. This suggests that its surface may be composed of dark, colorless rock. Jupiter's rings Jupiter's three rings came as a surprise when NASA's Voyager 1 spacecraft discovered them around the planet's equator in 1979. Each are much fainter than Saturn's rings. The main ring is flattened. It is about 20 miles (30 km) thick and more than 4,000 miles (6,400 km) wide.

The inner cloud-like ring, called the halo, is roughly 12,000 miles (20,000 km) thick. The halo extends halfway from the main ring down to the planet's cloud tops and expands by interaction with Jupiter's magnetic field. Both the main ring and halo are composed of small, dark particles. The third ring, known as the gossamer ring because of its transparency, is actually three rings of microscopic debris from three of Jupiter's moons, Amalthea, Thebe and Adrastea. It is probably made up of dust particles less than 10 microns in diameter, about the same size of the particles found in cigarette smoke, and extends to an outer edge of about 80,000 miles (129,000 km) from the center of the planet and inward to about 18,600 miles (30,000 km). Ripples in the rings of both Jupiter and Saturn may be signs of impacts from comets and asteroids.

Research & exploration Seven missions have flown by Jupiter — Pioneer 10 , Pioneer 11 , Voyager 1 , Voyager 2 , Ulysses, Cassini and New Horizons — while another, NASA's Galileo, actually orbited the planet. Pioneer 10 revealed how dangerous Jupiter's radiation belt is, while Pioneer 11 provided data on the Great Red Spot and close-up pictures of its polar region. Voyager 1 and 2 helped astronomers create the first detailed maps of the Galilean satellites, discovered Jupiter's rings, revealed sulfur volcanoes on Io, and saw lightning in Jupiter's clouds. Ulysses discovered the solar wind has a much greater impact on Jupiter's magnetosphere than before suggested. New Horizons took close-up pictures of Jupiter and its largest moons. In 1995, Galileo sent a probe plunging towards Jupiter, making the first direct measurements of its atmosphere and measuring the amount of water and other chemicals there. When Galileo ran low on fuel, the craft was intentionally crashed into Jupiter's atmosphere to avoid any risk of it slamming into and contaminating Europa, which might have an ocean below its surface capable of supporting life.

Another spacecraft, named Juno , is heading toward Jupiter and will reach the planet in 2016. It will study Jupiter from a polar orbit to figure out how it and the rest of the solar system formed, which could shed light on how alien planetary systems might have developed. Jupiter's gravitational impact on the solar system As the most massive body in the solar system after the sun, the pull of Jupiter's gravity has helped shape the fate of our system. It may have violently hurled Neptune and Uranus outward , according to calculations published in the journal Nature. Jupiter, along with Saturn, may have slung a barrage of debris toward the inner planets early in the system's history, according to an article in Science magazine. It may even nowadays help keep asteroids from bombarding Earth, and recent events certainly have shown that it can absorb potentially deadly impacts . Currently, Jupiter's gravitational field influences numerous asteroids that have clustered into the regions preceding and following Jupiter in its orbit around the sun. These are known as the Trojan asteroids, after three large asteroids there, Agamemnon, Achilles and Hector, names drawn from the Iliad, Homer's epic about the Trojan War.

Possibility of life on Jupiter If one were to dive into Jupiter's atmosphere , one would discover it to grow warmer with depth, reaching room temperature, or 70 degrees F (21 degrees C), at an altitude where the atmospheric pressure is about 10 times as great as it is on Earth. Scientists have conjectured that if Jupiter has any form of life, it might dwell at this level, and would have to be airborne. However, researchers have found no evidence for life on Jupiter. Additional reporting by Nola Taylor Redd, Space.com Contributor Explore the solar system Why Jupiter's Great Red Spot Has Lasted So Long Why Jupiter's Great Red Spot Has Lasted So Long By Charles Q. Choi , SPACE.com Contributor | November 25, 2013 07:01am ET MORE Close-up of Jupiter's Great Red Spot as seen by a Voyager spacecraft. Credit: NASA/JPL-Caltech The mystery of why Jupiter's Great Red Spot did not vanish centuries ago may now be solved, and the findings could help reveal more clues about the vortices in Earth's oceans and the nurseries of stars and planets, researchers say.

The Great Red Spot is the most noticeable feature on Jupiter's surface — a storm about 12,400 miles (20,000 kilometers) long and 7,500 miles (12,000 km) wide, about two to three times larger than Earth. Winds at its oval edges can reach up to 425 mph (680 km/h). This giant storm was first recorded in 1831 but may have first been discovered in 1665. "Based on current theories, the Great Red Spot should have disappeared after several decades," researcher Pedram Hassanzadeh, a geophysical fluid dynamicist at Harvard University,said in a statement. "Instead, it has been there for hundreds of years." [ Photos: Most Powerful Storms in the Solar System ] Vortices like the Great Red Spot can dissipate because of many factors. For instance, waves and turbulence in and around the storm sap its winds of energy. It also loses energy by radiating heat. Moreover, the Great Red Spot rests between two powerful jet streams in Jupiter's atmosphere that flow in opposite directions and may slow down its spinning.

Some researchers suggest that large vortices such as the Great Red Spot gain energy and survive by absorbing smaller vortices . However, "this does not happen often enough to explain the Red Spot's longevity," researcher Philip Marcus, a fluid dynamicist and planetary scientist at the University of California, Berkeley,said in a statement. Jupiter, the giant of our solar system, is as fascinating as it is photogenic. How much do you know about the king of the planets? Start Over | More Quizzes The Great Red Spot is not the only mysterious vortex. In fact, vortices in general, including ones in Earth's oceans and atmosphere, often live much longer than current theories can explain. To help solve the mystery of the Great Red Spot's endurance, Hassanzadeh and Marcus developed a new 3D, high-resolution computer model of large vortices. Models of vortices generally focus on swirling horizontal winds, where most of the energy resides. Although vortices also have vertical flows, these have much less energy. Therefore, "in the past, most researchers either ignored the vertical flow because they thought it was not important, or they used simpler equations because it was so difficult to model," Hassanzadeh said.

The researchers now find that vertical flows hold the key to the Great Red Spot's longevity: When the storm loses energy, vertical flows move hot and cold gases in and out of the storm, restoring part of the vortex's energy. Their model also predicts radial flows that suck winds from the high-speed jet streams around the Great Red Spot toward the storm's center, helping it last longer. Together, vortices — whether on Jupiter or in Earth's oceans — may decay up to 100 times slower than researchers previously thought. "Some vortices in the oceans have been observed to last for several years and are believed to play an important role in the oceanic ecosystem and ocean-atmosphere interaction," Marcustold SPACE.com. In addition, "vortices with physics very similar to the Great Red Spot are believed to contribute to star and planet formation processes, which would require them to last for several million years. Both oceanic and astrophysical vortices are subjected to dissipating processes, and the mechanism described here for the longevity of the Great Red Spot presents a very plausible explanation for their longevity as well." The scientists caution that their model does not entirely explain the Great Red Spot's long life span.

They suggest that occasional mergers with smaller vortices may help prolong the giant storm's life as well, and have begun modifying their computer model to test this idea. In addition, their "current model does not account for compressibility of the flow or sphericity of the planet," Hassanzadeh told SPACE.com. "Although we believe that these effects do not change the conclusions of our work, we are planning to modify our model in the next step and include these effects." The scientists will detail their findings Nov. 25 at the annual meeting of the American Physical Society's Division of Fluid Dynamics in Pittsburgh. Follow us @Spacedotcom , Facebook and Google+ . Original article on SPACE.com . Editor's Recommendations NASA - The Great Dark Spot The Great Dark Spot The Cassini spacecraft has photographed an extraordinary dark cloud on Jupiter twice as big as Earth itself. Listen to this story via streaming audio , a downloadable file , or get help . March 12, 2003: For more than a century astronomers thought that the Great Red Spot was the biggest thing on Jupiter. Not anymore. Images from NASA's Cassini spacecraft have revealed something at least as large. The Great Dark Spot.

"I was totally blown away when I saw it -- a dark cloud twice as big as Earth swirling around Jupiter's north pole," says Bob West, a planetary scientist at the Jet Propulsion Laboratory. Right: This composite of Cassini ultra-violet (UV) images reveals the "Great Dark Spot" swirling near Jupiter's north pole. Jupiter's auroral zone is denoted by the blue curve. [ more ] West has been chasing this cloud for some time. He first saw it -- "just a glimpse," says West -- in an ultraviolet (UV) picture of Jupiter taken by the Hubble Space Telescope in 1997. But it only appeared in one image out of many spanning a period of years. "I didn't know what to make of it," he recalls. Now he knows. "The Cassini spacecraft was en route to Saturn in 2000 when it passed by Jupiter and had a good view of the planet's north pole," says West. "At first there was nothing unusual -- just ordinary polar clouds. Then the Dark Spot emerged." For weeks Cassini's UV-sensitive cameras watched as the cloud grew into an oval the size of the Great Red Spot itself.

It swirled, darkened and changed shape until, as Cassini was departing, it began to fade again. (See the entire movie .) "The Dark Spot is ephemeral," says West. That's probably why Hubble saw it only once. And if Cassini had arrived a month or two later, it might not have seen the Dark Spot at all. Instead, Cassini's cameras monitored the cloud for 11 straight weeks, and those data have allowed West to draw some conclusions: "The Great Dark Spot and the Great Red Spot are entirely different," he says. The Great Red Spot is deep. "It's a high-pressure storm system rooted in Jupiter's troposphere far below the cloudtops. The Great Dark Spot is apparently shallow and confined to Jupiter's high stratosphere." Left: The Great Red Spot is a long-lasting storm rooted deep in Jupiter's atmosphere. [ more ] West believes the Dark Spot is a curious side-effect of auroras on Jupiter. "Jupiter has Northern Lights just as Earth does, although on Jupiter they are hundreds to thousands of times more powerful," says West. Auroras happen when electrons and ions rain down on the polar atmosphere and cause the air to glow where they hit.

Here on Earth, auroras are usually sparked by solar wind gusts. The solar wind can also trigger auroras on Jupiter, but it's not necessary; on Jupiter the planet itself energizes Northern Lights. "Jupiter's magnetic field is a huge reservoir of charged particles," explains West. "These particles are accelerated poleward by the 11-hour rotation of Jupiter and its magnetic field. Thus, auroras on Jupiter are almost always active." "High-energy electrons that hit Jupiter's atmosphere not only cause auroras, but also break apart methane (CH4), which is more abundant on Jupiter than it is on Earth," says West. "Fragments of methane molecules combine with ambient hydrogen to form acetylene C2H2. That's the basic building block. Acetylene combines with other carbon- and hydrogen-containing molecules to build even more complex molecules, which eventually condense into dark droplets." Above: A Hubble Space Telescope image of Northern Lights on Jupiter. [ more ] If West is right, the Great Dark Spot is a haze of hydrocarbon-rich droplets floating in the uppermost layers of Jupiter's stratosphere. Such a haze would be prominent in UV images because hydrocarbon droplets are strong absorbers of UV radiation.

Indeed, the Great Dark Spot is invisible to the human eye. "It can only be seen in UV light." His idea fits the facts, but West remains puzzled: "There was no strong auroral display when the Great Dark Spot intensified in late 2000. What caused it to appear when Cassini was flying by? We don't know. This shows us that Jupiter's stratosphere is a more interesting place than we once thought." Furthermore, it can teach us something about our own planet. West explains: "This dark spot is trapped by a polar vortex -- a jet stream that encircles Jupiter's north pole." Fast-moving winds in the vortex act like an atmospheric wall, keeping the Dark Spot corralled at high latitudes. Similar vortices encircle Earth's polar regions. Our planet's Arctic vortex is disrupted somewhat by northern land masses, but the Antarctic vortex is better organized. It plays a key role in confining the ozone hole -- much as Jupiter's polar vortex confines the Great Dark Spot. Right: Earth's south polar ozone hole. [ more ] "Monitoring the Dark Spot could help us understand how planetary vortices work." For such studies, two planets are clearly better than one.

Meanwhile, West would be delighted just to see the Dark Spot again. "It's elusive," he says. But he's ready to be blown away ... any time. The Great Dark Spot | Science Mission Directorate Science Mission Directorate Mar 12, 2003 The Great Dark Spot The Cassini spacecraft has photographed an extraordinary dark cloud on Jupiter twice as big as Earth itself. Listen to this story via March 12, 2003: For more than a century astronomers thought that the Great Red Spot was the biggest thing on Jupiter. Not anymore. Images from NASA's Cassini spacecraft have revealed something at least as large. The Great Dark Spot. "I was totally blown away when I saw it--a dark cloud twice as big as Earth swirling around Jupiter's north pole," says Bob West, a planetary scientist at the Jet Propulsion Laboratory. Right: This composite of Cassini ultra-violet (UV) images reveals the "Great Dark Spot" swirling near Jupiter's north pole. Jupiter's auroral zone is denoted by the blue curve. [ more ] West has been chasing this cloud for some time.

He first saw it--"just a glimpse," says West--in an ultraviolet (UV) picture of Jupiter taken by the Hubble Space Telescope in 1997. But it only appeared in one image out of many spanning a period of years. "I didn't know what to make of it," he recalls. Sign up for EXPRESS SCIENCE NEWS delivery Now he knows. "The Cassini spacecraft was en route to Saturn in 2000 when it passed by Jupiter and had a good view of the planet's north pole," says West. "At first there was nothing unusual--just ordinary polar clouds. Then the Dark Spot emerged." For weeks Cassini's UV-sensitive cameras watched as the cloud grew into an oval the size of the Great Red Spot itself. It swirled, darkened and changed shape until, as Cassini was departing, it began to fade again. (See the entire movie .) "The Dark Spot is ephemeral," says West. That's probably why Hubble saw it only once. And if Cassini had arrived a month or two later, it might not have seen the Dark Spot at all.

Instead, Cassini's cameras monitored the cloud for 11 straight weeks, and those data have allowed West to draw some conclusions: "The Great Dark Spot and the Great Red Spot are entirely different," he says. The Great Red Spot is deep. "It's a high-pressure storm system rooted in Jupiter's troposphere far below the cloudtops. The Great Dark Spot is apparently shallow and confined to Jupiter's high stratosphere." Left: The Great Red Spot is a long-lasting storm rooted deep in Jupiter's atmosphere. [ more ] West believes the Dark Spot is a curious side-effect of auroras on Jupiter. "Jupiter has Northern Lights just as Earth does, although on Jupiter they are hundreds to thousands of times more powerful," says West. Auroras happen when electrons and ions rain down on the polar atmosphere and cause the air to glow where they hit. Here on Earth, auroras are usually sparked by solar wind gusts. The solar wind can also trigger auroras on Jupiter, but it's not necessary: On Jupiter, the planet itself energizes Northern Lights. "Jupiter's magnetic field is a huge reservoir of charged particles," explains West. "These particles are accelerated poleward by the 11-hour rotation of Jupiter and its magnetic field.

Thus, auroras on Jupiter are almost always active." "High-energy electrons that hit Jupiter's atmosphere not only cause auroras, but also break apart methane (CH4), which is more abundant on Jupiter than it is on Earth," says West. "Fragments of methane molecules combine with ambient hydrogen to form acetylene C2H2. That's the basic building block. Acetylene combines with other carbon- and hydrogen-containing molecules to build even more complex molecules, which eventually condense into dark droplets." Above: A Hubble Space Telescope image of Northern Lights on Jupiter. [ more ] If West is right, the Great Dark Spot is a haze of hydrocarbon-rich droplets floating in the uppermost layers of Jupiter's stratosphere. Such a haze would be prominent in UV images because hydrocarbon droplets are strong absorbers of UV radiation. Indeed, the Great Dark Spot is invisible to the human eye. "It can only be seen in UV light." His idea fits the facts, but West remains puzzled: "There was no strong auroral display when the Great Dark Spot intensified in late 2000. What caused it to appear when Cassini was flying by? We don't know.

This shows us that Jupiter's stratosphere is a more interesting place than we once thought." Furthermore, it can teach us something about our own planet. West explains: "This dark spot is trapped by a polar vortex--a jet stream that encircles Jupiter's north pole." Fast-moving winds in the vortex act like an atmospheric wall, keeping the Dark Spot corralled at high latitudes. Similar vortices encircle Earth's polar regions. Our planet's Arctic vortex is disrupted somewhat by northern land masses, but the Antarctic vortex is better organized. It plays a key role in confining the ozone hole--much as Jupiter's polar vortex confines the Great Dark Spot. Right: Earth's south polar ozone hole. [ more ] "Monitoring the Dark Spot could help us understand how planetary vortices work." For such studies, two planets are clearly better than one. Meanwhile, West would be delighted just to see the Dark Spot again. "It's elusive," he says. But he's ready to be blown away ... any time. Web Links Puzzling X-rays from Jupiter -- (Science@NASA) The Great Dark Spot isn't the only odd thing at Jupiter's north pole.

Astronomers using the Chandra X-ray Observatory have spotted a mysterious pulsing x-ray beacon there, too. Cassini Imaging Diary: Jupiter -- (University of Arizona) more images and movies from Cassini 's flyby of Jupiter. Rising storms revise story of Jupiter's stripes -- (NASA) Pictures of Jupiter, taken by a NASA spacecraft on its way to Saturn, are flipping at least one long-standing notion about Jupiter upside down. All About Planet Jupiter for Kids – Giant Red Spot « What does this planet look like? Jupiter, the fifth planet from the sun, is the largest planet in the solar system. It is the first of the “gas giants” and has no surface, though it may have a rocky core. Although it is only 1/1000th as massive as the sun, it is more than double as massive as all of the other planets in the solar system combined. Jupiter’s atmosphere is separated into different bands and gives the planet the appearance of having whitish and reddish layers with various spots, swirls and bubbles. Jupiter’s most notable feature, other than its size, is the great red spot, a football shaped area of intense storms.

Three Earths could fit inside the great red spot. The spot, which is a high pressure, stable storm with winds that gust over 400 miles per hour, is said to be somewhat similar to a hurricane. Recent studies have shown that the spot has actually shrunk and that the storm may be weakening. Scientists still don’t have an explanation for why the spot looks red. In addition, Jupiter also has a faint set of rings (probably made of dust) that wrap around the planet horizontally. How big is this planet? Jupiter is the largest planet in the solar system. It is nearly 318 times as massive as Earth, has the surface area of 122 Earths, and has 1,321 times the volume of Earth. How long does it take to orbit the sun? What is its gravity like? Gravitational force on Jupiter is 254% the gravitational force on Earth. A 100 pound Earthling would weigh about 254 pounds on Jupiter. How far is it from the sun? From the Earth? Jupiter is located an average of 466,000,000 miles from the sun.

At its closest point, Earth and Jupiter are more than 390,000,000 miles apart. At their farthest, the two planets are more than 576,000,000 miles apart. What is its atmosphere like? The atmosphere of Jupiter is about 86 percent hydrogen and 14 percent helium. Methane, water vapor and ammonia exist in trace amounts. The interior of Jupiter is denser, with about 71 percent hydrogen, 24 percent helium and five percent other elements. Occasionally, flashes of lightning are detected in the atmosphere of Jupiter. These electrical discharges are said to be at least 1,000 times as powerful as the typical lightning strike on Earth. What’s the temperature like? The average temperature in the cloud tops of planet Jupiter is -234 F, but if you were to descend from the cloud tops, closer to the interior of the planet (where the atmospheric pressure becomes about ten times what it is on Earth) the temperatures would actually be around 55 degrees F. If you were to descend farther, the temperatures would become incredibly hot. How many moons does it have?

Jupiter has at least 63 moons, more than any other planet. The four Galilean moons of Jupiter are the most massive. These moons were discovered by Galileo himself in 1610 and were the first moons discovered of any planet other than Earth’s. *Jupiter is the third brightest object in the sky after Venus and the Moon. *Recently, an amateur astronomer in Australia discovered an Earth-sized dent toward the southern pole of Jupiter. According to NASA, the dent was likely caused by a stray comet or chunk of ice. WTP: Jupiter: The Great Red Spot Previous ... Next ... Planet Profile ... Explorer ... Up a Level ... Home The Great Red Spot The colorful, wavy cloud pattern to the left of the Red Spot is a region of extraordinarily complex wave motion. This dramatic view of the Great Red Spot and its surroundings was taken February 25, 1979, when Voyager 1 was 9.2 million km (5.7 million mi) from Jupiter . An atmospheric system larger than Earth and more than 300 years old, the Great Red Spot remains a mystery. Swirling, storm-like features possibly associated with wind shear can be seen both to the left and above the Red Spot.

Great Red Spot | storm system, Jupiter | Britannica.com Great Red Spot Samuel Heinrich Schwabe Great Red Spot, a long-lived enormous storm system on the planet Jupiter and the most conspicuous feature of its visible cloud surface. It is generally reddish in colour, slightly oval in shape, and approximately 16,500 km (10,250 miles) wide—large enough to engulf Earth . It moves in longitude with respect to the clouds as Jupiter rotates but remains centred at about latitude 22° S. Jupiter’s Great Red Spot (top right) and the surrounding region, as seen from Voyager 1 on March 1, … NASA/JPL The first record of the Great Red Spot is a drawing made in 1831 by German amateur astronomer Samuel Heinrich Schwabe of the “Hollow” in which the spot sits. The Great Red Spot itself has been continuously observed since 1878 when it was described by American astronomer Carr Walter Pritchett. It may be the same storm as the so-called “Permanent Spot” that was discovered in 1665 by Italian astronomer Gian Domenico Cassini and last seen in 1713.

Detailed observations and measurements have been made by the Voyager and Galileo spacecraft. Seen through telescopes from Earth, it varies in colour from year to year from salmon-red to gray, when it may blend indistinguishably into the colouring of the surrounding cloud belts. High-resolution spacecraft pictures revealed that the feature’s pinkish cloud layer can be overlain from time to time by high-altitude white clouds, producing the gray impression seen from Earth. In the late 19th century the length of the spot was about 48,000 km (30,000 miles), and since then the spot has been shrinking. The Voyager spacecraft measured the spot’s length at 23,000 km (14,500 miles) in 1979. Since 2012 the spot has become more circular and has been shrinking at a faster rate of about 900 km (580 miles) per year. Meteorologically, the Great Red Spot is an anticyclonic circulation system—i.e., a high-pressure centre in the planet’s southern hemisphere.

Cameras carried by the Voyager 1 and 2 spacecraft revealed in 1979 that the entire system rotates counterclockwise with a period of about seven days, corresponding to wind velocities at its periphery of 400 km (250 miles) per hour. The source of the red coloration is unknown; suggestions range from compounds of sulfur and phosphorus to organic material, any of which could be produced by lightning discharges or by high-altitude photochemical reactions. The Great Red Spot extends well above Jupiter’s main cloud layers. False-colour infrared image of the Great Red Spot and its environs, based on observations made by … Photo NASA/JPL/Caltech (NASA photo # PIA00838) Britannica Stories Why is Jupiter's Great Red Spot … Red? - Sky & Telescope Sky & Telescope Download Your Free Astrophotography Primer Now from Sky & Telescope! * By: Kelly Beatty | November 18, 2014 Scientists think they've figured out what causes the mysterious ruddy coloring in the giant planet's enormous oval storm. Earlier this year, the Great Red Spot stood out prominently against Jupiter's bright zones and dark belts.

Damian Peach When it comes to well-known planetary features, Jupiter's iconic Great Red Spot is near the top of everyone's list. It's truly enormous — much bigger than Earth — though its girth has shrunk over the past decade. The Great Red Spot is as mysterious as it is majestic. Unlike hurricanes and cyclones on Earth, which come and go in a matter of days, this iconic oval has endured for centuries. Giovanni Battista Riccioli and Gian Domenico Cassini noted it during the mid-1600s, though it could well have existed well before then. Astronomers have long pondered what causes the GRS to be so red — at least most of the time (the intensity of its hue changes, varying from a dark salmon to nearly white). One important clue comes from the spot's overall structure and 5-day-long rotation. Unlike terrestrial hurricanes, which are low-pressure storms, the GRS is a high-pressure (anticyclonic) system that's much taller than the clouds surrounding it. The spot's cloudy interior is also relatively opaque, meaning whatever particles are coloring it must float near the top of this giant, buoyant bubble.

The Great Red Spot's appearance at three infrared wavelengths, as recorded by NASA's Galileo spacecraft in 1996, provides important clues to the big storm's characteristics. NASA / JPL / K. Baines For decades atmospheric chemists believed that the spot was tinted with phosphine (PH3), an unusual compound found in the Jovian atmosphere. But more recently attention has focused on sulfur and its colorful allotropes . One of Jupiter's three dense cloud layers consists of ammonium hydrosulfide (NH4SH), which, the thinking goes, could be dredged up by atmospheric convection and broken down by sunlight to form elemental sulfur. That's what Kevin Baines, Robert Carlson, and Thomas Momary (all at the Jet Propulsion Laboratory) had in mind when they began laboratory experiments to try to replicate the coloring process. Carlson irradiated ammonium hydrosulfide with ultraviolet light, to mimic sunlight. But the resulting compounds were bright green, not red! So the researchers instead tried irradiating a mixture of ammonia (NH3) and acetylene (C2H2), both of which exist in Jupiter's upper atmosphere.

The result was a red concoction of cyanide-like molecules with the general formula HxCyNz where x, y, and z vary. Better still, the reddish particles have a spectrum that closely matches what NASA's Cassini spacecraft recorded inside the Great Red Spot when it swept by Jupiter in late 2000 while en route to Saturn. Baines, Carlson, and Momary find that the best match involves particles just 400 nanometers across (the wavelength of blue light) thinly scattered in a layer only a few kilometers thick. The stuff looks red because it absorbs blue light strongly. "The model that fits is basically a 'crème brûlée' or 'strawberry-frosted cake' model," Baines explains, with a narrow layer of reddish material on top of the main, whitish cloud layer. So beneath its reddish veneer, created at a pressure level of roughly 300 millibars, the Great Red Spot would actually look rather bland. NASA's Cassini spacecraft captured the complex circulation inside the Great Red Spot when it swept past Jupiter (en route to Saturn) on December 29, 2000. NASA / JPL / Space Science Inst.

The spot's rotation isolates and confines the atmospheric gases inside it, allowing these reddish colorants (impress your friends: they're technically called chromophores) to accumulate. "The GRS acts as a cauldron," Baines explains, "confining materials and letting them cook." So why does the GRS's color vary so much over time? Apparently its hue depends on how much of ammonia and acetylene are present, their exact altitude, and how long they're exposed to sunlight. But the chemical conversion is rapid — Baines says they able to create the basic colors after just one day of "tanning" of the gas mixture in their lab tests. The three researchers presented their findings Friday at the annual meeting of the American Astronomical Society's Division for Planetary Sciences . A full account has been submitted to Icarus, but you can also find details in this JPL press release . Track down Jupiter and a host of other celestial sights with SkyWatch, our annual observing guide. Choose from the 2014 edition or the 2015 edition. CATEGORIES What is the Great Red Spot on Jupiter? | Cool Cosmos What is the Great Red Spot on Jupiter?

The Great Red Spot is a giant, spinning storm in Jupiter's atmosphere. It is like a hurricane on Earth, but it is much larger. Jupiter's Great Red Spot is more than twice the size of Earth! Winds inside this storm reach speeds of about 270 miles per hour. Nobody knows when the Great Red Spot first appeared on Jupiter, but it has been seen on Jupiter ever since people started looking through telescopes about 400 years ago. Continue the conversation on Jupiter's New Red Spot | Science Mission Directorate Science Mission Directorate + Play Audio | + Download Audio | + Historia en Español | + Join mailing list March 3, 2006: Backyard astronomers, grab your telescopes. Jupiter is growing a new red spot. Christopher Go of the Philippines photographed it on February 27th using an 11-inch telescope and a CCD camera: Above: Red spots on Jupiter, photographed by amateur astronomer Christopher Go on Feb. 27, 2006. [ Larger image ] The official name of this storm is "Oval BA," but "Red Jr." might be better. It's about half the size of the famous Great Red Spot and almost exactly the same color.

Oval BA first appeared in the year 2000 when three smaller spots collided and merged. Using Hubble and other telescopes, astronomers watched with great interest. A similar merger centuries ago may have created the original Great Red Spot, a storm twice as wide as our planet and at least 300 years old. Sign up for EXPRESS SCIENCE NEWS delivery At first, Oval BA remained white—the same color as the storms that combined to create it. But in recent months, things began to change: "The oval was white in November 2005, it slowly turned brown in December 2005, and red a few weeks ago," reports Go. "Now it is the same color as the Great Red Spot!" "Wow!" says Dr. Glenn Orton, an astronomer at JPL who specializes in studies of storms on Jupiter and other giant planets. "This is convincing. We've been monitoring Jupiter for years to see if Oval BA would turn red—and it finally seems to be happening." (Red Jr? Orton prefers "the not-so-Great Red Spot.") Why red? Curiously, no one knows precisely why the Great Red Spot itself is red.

A favorite idea is that the storm dredges material from deep beneath Jupiter's cloudtops and lifts it to high altitudes where solar ultraviolet radiation--via some unknown chemical reaction—produces the familiar brick color. "The Great Red Spot is the most powerful storm on Jupiter, indeed, in the whole solar system," says Orton. The top of the storm rises 8 km above surrounding clouds. "It takes a powerful storm to lift material so high," he adds. Above: Hubble images detail the birth of oval BA in 1997-2000. [ More ] Oval BA may have strengthened enough to do the same. Like the Great Red Spot, Red Jr. may be lifting material above the clouds where solar ultraviolet rays turn "chromophores" (color-changing compounds) red. If so, the deepening red is a sign that the storm is intensifying. "Some of Jupiter's white ovals have appeared slightly reddish before, for example in late 1999, but not often and not for long," says Dr. John Rogers, author of the book "Jupiter: The Giant Planet," which recounts telescopic observations of Jupiter for the last 100+ years.

"It will indeed be interesting to see if Oval BA becomes permanently red." See for yourself: Jupiter is easy to find in the dawn sky. Step outside before sunrise, look south and up: . Jupiter outshines everything around it. Small telescopes have no trouble making out Jupiter's cloudbelts and its four largest moons. Telescopes 10-inches or larger with CCD cameras should be able to track Red Jr. with ease. What's next? Will Red Jr. remain red? Will it grow or subside? Stay tuned for updates.

Question: Which planet has a 'great red spot'?
Answer: JUPITER